The present invention relates to a bone reaming system, and more particularly, to an apparatus and method for preparing specific geometries in the metaphyseal region of long bones.
Orthopedic surgery has been prevalent in recent years and the number of joint arthroplasty procedures is projected to grow exponentially in the future. Total knee replacement (TKR) is an example of joint arthroplasty. In TKR, the end surfaces of the femoral and tibial bones are resected and replaced with implants that may be made from metal, ceramic, polyethylene, or some combination thereof. In this procedure, the femoral and tibial implants may be fixed to the bone using cement, cementless biologic fixation or other known fixation means. While good TKR survivorship has been reported, it is known that these procedures may fail for reasons including incorrect alignment, loosening, osteolysis, infection, and the like. If a TKR procedure fails, a revision TKR procedure may be required.
In revision TKR, the primary implant components typically need to be removed, leaving defects or voids in the metaphyseal regions of the long bones on which they were implanted. Defects may be the result of removing the implants, the cement, other fixation means such as screws, or bone regions compromised by infection. The void size and geometry are unique for each patient and it is critical to augment these defect regions to ensure proper structural support for revision TKR implants.
In these revision TKR procedures, the augments available to address these bone defects are generally offered in limited sizes and shapes which do not consider the unique defect geometries of a particular patient. At least in part, the limitation of augment offerings is due to inability of current preparation instrument systems to prepare complex and non-uniform geometries. Thus, it is common place for patients to have excessive bone removed from their specific defect region in order to receive standard augment prostheses. Moreover, in some cases, an impaction based preparation technique such as broaching is used to prepare a bone defect region during revision surgery. Given that the bone in the defect region is already compromised, this impaction technique may lead to bone fractures which further worsen the patient condition and require addition intervention.
Therefore there exists a need for bone preparation system that will allow for complex and non-uniform geometries to be created during a preparation of the bone using non-impaction means.